First I am neither a mathematician nor an engineer. I speak of airplane design features as a user and not as a designer. If my terms offend, just correct me.

Nearly all the controls and the overall stability of the airplane are dynamic and not static. Given a certain trim airspeed, dynamic neutral stability will bracket that airspeed to prevent stall. The airplane cannot stall itself. If we pay attention to what the airplane wants to do during pitch up, pitch down, or bank, we will never inadvertently stall the airplane. The elevator, what Wolfgang called the flippers, is mounted on the longitudinal axis such that it will dynamically control the pitch of that axis. The rudder is mounted on the longitudinal axis such that it will dynamically control the yaw of that axis. The tractor mounted thrust producer is mounted on the front of the longitudinal axis such that its propeller (rotary wing) will cause forward motion and thus airspeed and also will blast extra relative wind on the inner part of the wing. Dynamic throttle movement brackets amount of thrust component of lift and, other than zoom reserve airspeed and potential energy of altitude, brackets airspeed. This complicated combination of energy sources makes throttle the most accurate dynamic control of glide angle and rate of descent when slow enough (sink without considerable thrust) to become dynamic. Zoom reserve airspeed and potential energy of altitude (potential airspeed) are airspeed available temporarily with or without thrust. The elevator trim control surface is mounted on the longitudinal axis such that it holds elevator pressure lightly but can be overcome with dynamic elevator movement. The rudder trim control surface is mounted on the rudder such that it holds rudder pressure lightly but can be overcome with dynamic rudder movement.

The two ailerons, the really different and complicated control surfaces, move dynamically individually but move opposite each other but the control effect is not exactly opposite and while it functions as our main roll control, it also creates adverse yaw or opposite of desired yaw control with the rudder. This is because the down aileron creates more lift on that wing and therefor more induced drag than the up aileron. Various design features to mitigate this, save that of the Ercoupe, do not eliminate the undesired control effect of the nose yawing opposite the roll unless we first move the rudder to cause desired yaw in the same direction of the desired roll. Rudder must pull aileron. Pushing aileron or step on the ball to react to the resultant slip works at high altitude but is dangerously late where horizontal space is limited and especially when trying to bracket the centerline on short final, where we don't want to turn anyway. Because aileron is mounted out on the end of the lateral axis, it requires either the funny banana shaped bell crank of the Ercoupe or a computer to be dynamically balanced. Leading rudder is the best we can do. Rudder must pull the down aileron wing forward. Once that aileron goes down, it is too late. When slow or in rough air, aileron to level wing can be dangerously late unless we at least lead a lot of rudder. And if we bracket the target when we don't want to bank or turn anyway, walking the rudders levels the wing or stabilizes it in the desired bank for drift control.

"The law of the roller coaster" or "airspeed is altitude and altitude is airspeed" from Stick and Rudder or zoom reserve airspeed and potential energy of altitude are natural dynamic energy that is positive when managed.

Thermal energy, updraft when warmer and downdraft when cooler, is natural dynamic energy that is positive when managed.

Variations in terrain, quite dynamic in the mountains and high desert, direct wind energy in ways that create orographic lift when managed.

Wind energy dynamically increasing relative wind and decreasing ground speed or adversely decreasing relative wind and increasing ground speed in tailwind and causing drift left and right in crosswind and dynamically increasing radius of turn downwind and decreasing radius of turn upwind and such can be positive when managed.

Ground effect energy dynamically increases acceleration for safety on takeoff but also fights deceleration on landing, but can be positive when managed.

Prior planning prevents pitifully poor performance, but energy management and paying attention to what the airplane wants to do can make the difference for those of us less organized. Move the controls individually to see what each one does. Manage all energy available for extra free performance. Learn to fly first and then learn to fly solely by reference to instruments. May the force (energy well managed) be with you.

Another great Sunday morning sermon from my Energy Preacher . Thanks Jim .

I have always respected the calm smoothness of the slower turning engines like the 65 hp and 90 hp Continental, O-300 Continental, the Pratt and Whitney R-985, the O-290 Lycoming, and 235 hp O-540 Lycoming. Not as powerful as the turned up ones, but they balance well in the airplanes they are mounted in and teach us to fly the wing a bit and manage all energy available. Because the front seat area of the Stearman allowed no larger than a 200 gallon hopper to be mounted, however, the 450 hp of the R-985 made it a really slow hot dog. Its reliable steady climb was unique in the airplanes I flew. Not even thinking about climb or turn without ground effect energy zoom reserve airspeed or potential energy of altitude zoom reserve airspeed or down drainage egress zoom reserve airspeed or thermal lift or orographic lift was more common for me. Defaulting the energy management turn other than in instrument flight was necessary for safety. The engine thrust of the Stearman and other high power to weight airplanes can spoil pilots and cause them to not seek and manage all energy available.

A problem with the common Stromberg carburetors on those small Continental engines was the engine gulp/gasp, lasting a couple seconds, when we moved the throttle aggressively. This made the closed throttle approach glide normal for beginning students. This led to the round out and hold off technique that Wolfgang called the easier beginning landing technique. Round engines like the R-985 had better carburetors and response to rapid throttle movement was rapid and as wonderful as with your Harley Davidson motorcycle. So Wolfgang touted the "stall-down," actually a power pitch approach as the experienced pilot approach. With the little Continental trainers, deceleration was accomplished with the throttle closes... a class act spot landing trick.

We now have reliable engines, good rapid response carburetors, and generally lots of flat space on airports prior to the numbers. And power/pitch, with a dynamic throttle for deceleration (increase in power as airspeed slows) and very exact glide angle and rate of descent control, is by far the easier landing technique. What is wrong with accurately controlling both the exact touchdown spot and the softness of the touchdown with power.

I agree with requiring the stabilized 1.3 Vso approach to safely get up to where we used to start the approach...short (quarter mile) final. If we can get to a workable altitude, steep or shallow glide angle is fine, at 1.3 Vso a quarter mile out, and we use a deceleration and power/pitch short final, the outcome of the landing is little in doubt.